Improvement in the construction of car-brakes



1. w. MUFFITT.

Construction'of Gar-Brakes. N0.l47,8v56 Patented Feb,24,`1874.

Wl'zwf. fie Vada/1 UNITED S'rnitn's JOHN W. MOFFITT, OF HARRISBURG, PENNSYLVANIA.

IMPROVEMENT IN THE CNSTRUCTION OF CAR-BRAKES.

Specification forming part of Letters Patent No. 147,856, dated February 24, 1874; application filed October f2, 1873.

To all whom 'it may concern Be it known that I, JOHN W. Morrrr'r, of the city of Harrisburg, county of Dauphin and State of Pennsylvania, have invented an Improved Brake-Shoe for Cars, of which the following is a specification:

The objects of my invention are, first, to render the liner reversible and sidewise detachable from the holder without forward or vertical displacement, the interlocking' parts being plain transverselysquare Walls and abutments; second, to secure strength in the liner and tenons thereon, as well as strength and plain construction in the holder, by avoiding deep incisions in the liner and difficult core-work in the latter 5 third, to hitch the liner reliably in place in the holder by a gravitating lockin g-bolt, arranged nearly vertically in the' upper abutment'of the holder, the office of said bolt being Y simply to curb and direct the liner relativel-yfto sidewise displacement by detaining its upper tenon in the upper recess of the holder in a peculiar manner, as hereinafter more fully set forth.

In the accompanying drawings making a part of this specification, Figure l represents the liner applied in proper position on the holder and the locking-bolt inserted. Fig. 2 is a rear view of the liner.

view. of the liner. Fig. 4 is a side view of the holder and the locking-bolt detached.

rihe liner C has the similar tenons A B formed on its rear side, located and in form as shown, having their obverse sides cut beveled or dovetailed, and their adjacent sides made square with the tangent to the circle of the liner, as shown in Figs. l and 3, and having vertical recesses G G in the body of the tenons cut in 'from the beveled side on their crowns, as shown in Figs. 1 and 2, and said recesses or grooves are made toadmit the locking-bolt about midway transversely, requiring' the remainder of the cross-section of said bolt to lie or retreat in a corresponding recessl in the wall of the upper tenon-recess in the holder, as shown in Fig. l. The lockingbolt thus enters both tenon and Wall of recess for the tenon, as a tongue in adjacent grooves, to curb and direct the liner relatively to side- Wise displacement. The contour of the holderabutments L L D corresponds with the upper Fig. 3 is an edge` and under sides of the tenons 4A B, and the iioors of the recesses m u are in a plane parallel with the tangent to the circle of the liner. The fore parts of the abutments project against and conform to the convex back of the liner, which they support to increase its strength. The recesses m n are made shallowr relative to frame d D e of the holder, thus econon'iizing its strength about the brake-bar, and as a base for the abutments L L. The recesses m a and the tenons A B are spaced equally distant from the indicated radius It of the circle of the liner. The faces of the tenons and the walls ofthe said recesses are transversely square and plain to allow the tenons a free exit sidewise from the recesses without forward or vertical shifting of the liner in the act of displacing it, thus avoiding the obstacles in-the way in the usual' mode of detaching the liner from the holder. The tractionon the liner is mainly vertical, and the tenons are made strong in that direction, both tenons being made to hug the seats made for them in the holder, and the lower tenon` is alsormade, by its beveled side, to hug the holder-frame. rlhe upper end of the liner is hitched and directed by the locking-bolt S, in the manner set forth, and the lower end is left free. The square form of the interlocking tenon and recess, and the meas.

ure of support given the liner by the lockingbolt, are sufficient to limit the lower end play of the liner. A limited play on said lower end is deemed to be favorable to the life and service of the brake mechanism, as a rigid and unyielding continuity of the parts composing brake renders the brake liable to snaps and Wrenches by the lateral tendency of the friction of the liner on the slightly-flared tread of the car-wheel. The locking-bolt S (shown in Fig. 4) is a tlat angular bar, provided with a longitudinal slot, a, in its body, and has its lower corner, next the liner, clipped or beveled that it may readily enter the cavity made for it. It is irremovably hitched in its cavity by a Xed transverse rivet, P, as shown in Fig. 1, partially to the rear of the tenon A or B, and partially in said tenon, so that the flat sides of the bolt may serve not only as a detent for the upper tenon, but also as a guide to direct the vertical alignment of the liner. Said locking-bolt is confined to the cavity 2 aeee made for it by a rivet, P, and the bolt may be raised suiieiently (the rivet-shank traveling in the slot cut therein) to free its lower end from its bite in the tenon. A worn-out liner may thus be replaced by a new one without undoing a bolt and nut, or other device requiring time and tools; and the interloeked connection of the liner and holder is proof against the concussion incident to braking, the locking-bolt, actuated by gravit-y alone, being` reliable for the constant performance of its oiiiee.

This brake-shoe is adapted for use on freightcars as Well as on passengercu's. rlhe latter, having the brakes a-pplied from the outside of the pair of Wheels of the truck, are more accessible, and have no exterior obstructing parts, to which my shoe, as patented May 6, 1873, has been successfully applied in practice; but the foriner-freiglit-cars generallyhave the brakes applied between the Wheels of the truck, Where the truck-log is in the Way of the lock-bar if more horizontally directed, as shown to be the case in said patent. This change of direction of the lock-bar, to overcome said obstruction, necessitated a change of the form of the tenons on the liner and tenon-frontlets in the holder, as is set forth hereinbefore. It is plain that my present application is superior in results, and this has been. proved by practice.

Having thus fully described my invention, what I desire to secure by Letters Iatent of the United States isl. rIhe combination of the holder L L D d e, liner O, and slotted lock-bar S, all constructed to operate as and for the purpose set forth.

2. The tenons A B, vertically grooved onf their ends, beveled exteriorly, and squared interiorly, substantially as and for the purpose set forth.

In testimony that I clailn the foregoing as my invention, I have hereunto set my hand this 13th day of September, 1873.

\Vitnesses: JOHN NV. MOFFITT.

TnEorHrLUs WEAVER, PETER STUCKER. 

